WAEC - Mathematics (1992 - No. 29)
Sin 60° has the same value as I. Sin 120° II. cos 240° III. -sin 150° IV. cos 210° V. sin 240°
I only
II only
IV only
III only
IV and V only
Giải thích
In the second quadrant, \(\sin 120 = \sin (180 - 120)\)
= \(\sin 60\)